1. Technical Field
The present invention relates to an electrophoretic display device and a method of manufacturing electrophoretic display device.
2. Related Art
Generally, electrophoretic display devices that have an electrophoretic dispersion liquid including a liquid dispersion medium and electrophoretic particles and utilize change of optical characteristics of the electrophoretic dispersion liquid according to application of an electric field for changing the distribution state of the electrophoretic particles have been known. The electrophoretic display devices do not need a back light, and accordingly, cost reduction and a decrease in the thickness can be achieved. In addition, the electrophoretic display devices have a memory effect of display in addition to a wide viewing angle and high contrast, and thus, the electrophoretic display devices have attracted attention as next-generation display devices.
In order to display an image by using the electrophoretic display devices, an image signal is temporarily stored in a memory circuit through a switching element. Then, the image signal stored in the memory circuit is directly input to a pixel electrode (a first electrode) so as to apply an electric potential to a pixel electrode. Then, an electric potential difference between the pixel electrode and an opposing electrode (a second electrode) is generated. Accordingly, an electrophoretic element is operated so as to display an image (for example, see JP-A-2003-84314).
However, in order to display an image by using the electrophoretic display device, a voltage, for example, of about 15 V is needed to be applied between electrodes that pinch the electrophoretic particles. In such a case, when different (inverted) colors such as black and white colors are displayed by adjacent pixels, different electric potentials are applied to the pixel electrodes of the adjacent pixels. Then, a large electric potential is generated between the adjacent pixel electrodes, and thereby a leakage current is generated between the adjacent pixel electrodes through a conductive adhesive layer disposed on the pixel electrode or the like.
Even when the leakage current is small for each one pixel, the leakage current becomes large for the entire display unit of the electrophoretic display device, and accordingly, the power consumption increases. In addition, when the inverted display area increases and display becomes complex in accompaniment with the increase of the inverted display area, the power consumption increases.
In addition, the pixel electrode may cause a chemical reaction due to generation of the leakage current. Accordingly, particularly when the electrophoretic display device is used for a long time, the reliability thereof may deteriorate.